If cancer cells lack a certain protein, it could be much easier for them to penetrate healthy body tissue, the first step towards forming metastases. Scientists at the Pharmacology Institute of the University of Heidelberg have discovered the previously unknown cell signal factor SCAI (suppressor of cancer cell invasion), which inhibits the movement and spread of tumor cells in laboratory tests. When the factor’s functioning was disrupted, the cancer cells moved much more effectively in what are known as three-dimensional matrix systems, which imitate some of the tissue properties of the human body.

“The protein is apparently suppressed in many types of tumors, e.g. breast, lung, or thyroid,” explains Dr. Robert Grosse, head of the Emmy Noether Junior Research Group funded by the German Research Association (DFG) at the Pharmacology Institute. The new factor could be an interesting starting point for research into new mechanisms for fighting cancer. The research team’s results have now been published online in the prestigious international journal Nature Cell Biology.

Focus on particularly aggressive cancers

Tumor cells are extremely mobile and “adept” at penetrating healthy tissue to form metastases. They adapt to the consistency of the respective tissue by changing their shapes constantly and attach flexibly to surrounding tissues during movement with the help of special surface structures (receptors).

One of these receptors is what is known as b1-integrin, which is frequently formed in many tumors such as metastasizing breast cancer. “The cell signal factor SCAI controls the formation and function of b1-integrin,” says Dr. Robert Grosse. “If there is too little SCAI in tumor cells, then b1-integrin is overactive, so to speak. The cell can change more rapidly to a more aggressive form and penetrate surrounding tissue, a crucial step toward increased spreading of the tumor and the possible formation of metastases.”

In their recently published study, the Heidelberg researchers examined cells from skin cancer (melanoma) and breast cancer. In other projects, Dr. Robert Grosse’s team would like to study the function of the signal factor SCAI more closely in an animal model. “If the function of SCAI is confirmed to be decisive in the formation of especially aggressive tumor cells, this could be a promising starting point for developing new diagnostic methods or medication,” says the pharmacologist. It could also be possible to develop an agent that prevents the genetic suppression of the signal factor in cancer cells. But first the researchers need to better understand how the signal factor itself is regulated in the cell.

Heidelberg University Hospital is one of the largest and most prestigious medical centers in Germany. The Medical Faculty of Heidelberg University belongs to the internationally most renowned biomedical research institutions in Europe. Both institutions have the common goal of developing new therapies and implementing them rapidly for patients. With about 7,000 employees, training and qualification is an important issue. Every year, around 500,000 patients are treated on an inpatient or outpatient basis in more than 40 clinics and departments with 1,600 beds. Currently, about 3,100 future physicians are studying in Heidelberg; the reform Heidelberg Curriculum Medicinale (HeiCuMed) is one of the top medical training programs in Germany.